According to the media reports, 10 Downing Street chief mouser Larry "away" for a few days, so the power hungry Palmerston took the opportunity to dash into the home.

Chief mouser’ Palmerston, a rescue cat recruited from Battersea Dogs and Cats Home explores his new surroundings in Permanent Under Secretary, Simon McDonald’s office in the Foreign and Commonwealth Office in London.

British Foreign Secretary Boris Johnson’s cat has made a dramatic bid for power by sneaking into Prime Minister Theresa May’s 10 Downing street residence while the chief mouser there was away but was unceremoniously evicted by police officers.

Johnson inherited a new feline colleague at the Foreign and Commonwealth Office as well as his new role in the Cabinet — and his cheeky streak appears to have rubbed off on the cat.

Palmerston took his Downing Street ambitions further by sneaking in to Theresa May’s new residence while no one was looking.

10 Downing Street chief mouser Larry is believed to be “away” for a few days and power hungry Palmerston took the opportunity to dash into the home, media reports said.

The black-and-white cat, who was appointed Chief Mouser to the Foreign Office earlier this year after being adopted from Battersea Dogs and Cats Home, was unceremoniously evicted by police officers, The Telegraph reported.

He then sat outside the building, looking furious and even appeared to have a stand-off with a police officer.

Amid the post-referendum upheaval within the government, Palmerston and his No. 10 rival Larry have been at each others’ throats recently.

One violent clash outside the Foreign Office is thought to have resulted in a paw injury to Larry which required veterinary treatment.

No. 10’s cat was put on bed rest for a few days as he licked his wounds.

Watch| Palmerston was caught on video earlier this week in a spat with No 10’s Larry the Cat